For those that don't remember the early days of ASRock, the company started out making some rather unusual motherboards, often with some wild and wacky upgrade paths, such as both a slot and a socket for a CPU or both AGP and PCIe graphics card slots. Since then, ASRock has become a much more mainstream motherboard maker, but the company appears to have gone back to its roots with what the company calls the X670 Xpansion Kit. Right now, the expansion card appears to be working with the B650 LiveMixer motherboard and it's unknown if it's compatible with other models from ASRock. It seems to be limited to ASRock motherboards only, due to the fact that the add-in card requires not only a x4 PCIe slot with all lanes attached, on the motherboard, but also a custom cable that is most likely for "low-speed" I/O's such as I2C, SPI and so on.
As the name suggests, the X670 Xpansion Kit allows B650 motherboards to be turned into X670 motherboards, more or less. The card is home to a second chipset, which enables not only two additional M.2 slots for PCIe 4.0 NVMe SSDs, but it also features two SATA ports, a 10 Gbps USB-C port, three USB-A ports and—maybe most interestingly—a 10 Gbps Ethernet interface. It's unclear if this will be a retail product, but the card provided to Level1Techs doesn't appear to be an engineer unit, but a full retail ready product. It's definitely an interesting upgrade path for those that have invested in a B650 motherboard and there's no real reason why this shouldn't work as well as having the second chipset on the motherboard, especially as ASRock appears to have fitted a signal re-driver on the add-in card to make sure the PCIe signals are handled properly.
